diff --git a/dom/events/EventStateManager.cpp b/dom/events/EventStateManager.cpp
index 9ec8d4533835..789fb4ec2795 100644
--- a/dom/events/EventStateManager.cpp
+++ b/dom/events/EventStateManager.cpp
@@ -2002,6 +2002,7 @@ EventStateManager::DoScrollZoom(nsIFrame* aTargetFrame,
       } else {
         ChangeTextSize(change);
       }
+      EnsureDocument(mPresContext);
       nsContentUtils::DispatchChromeEvent(mDocument, static_cast<nsIDocument*>(mDocument),
                                           NS_LITERAL_STRING("ZoomChangeUsingMouseWheel"),
                                           true, true);